Blasting powder and method of manufacturing the same



atented eb. 16, I932 BOY LINDEN HILL, 0} WILMINGTON, DELAWARE, ASSIGNOR 'I'O ATLAS POWDER COM- PANY, 0F WILMINGTON, DELAWARE, A CORPORATION OF DIELLAWARE BLASTING-POWDER AN D METHOD OF FACT'URING THE SAME No Drawing. Original application filed February 26, 1929, Serial No. 342,955. Divided and this application filed December 26, 1929. Serial No. 416,739.

This application is a division of my copending application, Serial No. 342,955, filed ebruary 26th, 1929.

The object of the invention is to provide an improved explosive of the nature of black powder and method of manufacturing the same. As was stated in my aforesaid application, black blasting powder is one of the most useful of explosives. It finds many important applications; sells at a lower price than practically any of the detonating ex-- black powder mills, and equipment. Some of them present the difficulty that, when incorporated in intimate contact with the usual sodium nitrate or potassium nitrate of black powder, a greatly increased hygroscopicity factor is introduced and black powder, at its best, is not of great moisture resistance.

Further, various ingredients, which might be proposed for incorporation with black powder to strengthen it, have other individual disadvantages in one or more of such items as manufacture, handling, shipment,

'storage and application.

Some of the objects which should, desirably, be attained or approached in making stronger black blasting powder, are: that it be adapted for manufacture in the usual black powder mills; that there be no increase in cost over usual black powder; that normal black powder safety in manufacture, handling, shipment, storage and application be maintained; that the usual methods of handling black powder, in the respects mentioned, will apply; that there be no increase in hygroscopicity; that the product possess the capability of strength regulation, and that the high temperature of combustion and the deficiency of oxygen of regular black powder be utilized to assist in increasing the strength factor.

Increased black powder strength without any, or at least without a proportional increase in cost, represents a distinct direct saving to the consumer in powder purchases. It oflers further saving in less drilling, because of possible increased spacing of holes and less springing of holes because of the lack of necessity of getting so much powder in the holes, to accomplish the desired work.

This invention provides a modification of black blasting powder, which will be characterized by most of the properties and the economy of usual black blasting powder, but with various degrees of increased strength.

More specifically, it concerns the production of blasting powder consisting of intermingled particles of usual black blasting powder and specially treated ammonium nitrate, in such form that the alkali metal nitrate of usual blasting powder is not in such intimate contact with the ammonium nitrate as to cause increased hygroscopicity from this cause, and providing-treatment of the ammonium nitrate to aid in the ready combustion or entrance into the explosive reaction.

A previously filed application of mine, (my co-pending application No. 315,106, filed October 26th, 1928) deals with grains of oxygen carrying explosive salt, as ammonium nitrate, intermingled with grains of usual black blasting powder, in such manner as to provide against the hygroscopicity resulting from intimate contact of alkali metal nitrate and ammonium nitrate, but depends solely on the reaction heat of the usual black powder to cause energy releasing decomposition of the ammonium nitrate. When the percentage of ammonium nitrate present is too high, or the explosive is insufliciently confined, this dependence may not be suflicient for best results.

I now find .that I can provide for a. more ready liberation of the energy of ammonium nitrate under the initiating influence of burning black powder by associating the ammonium nitrate intimately with combustible and oxygen deficient matter, before mingling I It is not intended to be used alone. However,

the entire composition is potentially gas forming on decomposition and possesses excellent strength possibilities. I mix the resultant product, consisting of ammonium nitrate, sulphur and charcoal, in any desired perature.

proportions with the usual alkali metal nitrate black powder. This latter material burns with great rapidity, accompanied by the development of much heat and high tem- These factors initiate and carry on the complete conversion of the ammonium nitrate product into highly expanded gas and water vapor, and with a resultant high degree of blasting energy.

This intimate mixing of the sulphur and charcoal with ammonium nitrate, prior to bringing the latter into association with alkali metal nitrate, such as sodium nitrate, for

example, prevents intimate contact between the ammonium nitrate and the alkali metal nitrate. In the ordinary black blasting powder, sodium nitrate, for example, is incorporated with and embedded in the associated sulphur and charcoal. Further, the resultant of ammonium nitrate and ammonium perchlorate intimately associated with and having a protective coating of sulphur and charcoal and mingled with whole black blasting powder.

3. A blasting medium consisting of grains of ammonium nitrate coated with sulphur and charcoal and the whole mingled with an alkali metal nitrate black blasing powder.

4. A blasting medium consisting of'ammonium nitrate coated with a protecting coating comprising charcoal, the whole intermixed with the grains of alkali metal nitrate black blasting powder.

5. The herein described process of preparing a blasting powder which combines the advantages of ammonium and alkali metal nitrate while avoiding the increase in hygroscopicity which the intimate content of ammonium nitrate and alkali metal nitrate would ordinarily involve, which consists of first mixing the ammonium nitrate intimately with sulphur and charcoal and thereafter intermixing the whole with alkali metal nitrate black blasting powder.

6. A blasting medium consisting of ammonium nitrate, the grains of which are coated with a protecting medium comprising sulphur and the whole intermixed with the grains of'black blasting powder.

In test mony whereof I affix my signature.

ROY LINDEN HILL.

product may be, and usually is, glazed or coated with some material such as graphite or aluminum dust in the same way the ammonium nitrate is covered and protected by its associated materials, and I avoid the difficulties which intimate contact of the nitrates would involve.

While I have described ammonium nitrate as belng the oxygen carrying explosive salt, that I preferably employ, it is to be understood that the invention contemplates the use of ammonium'perchlorate in the same re- I lation.

Having described my invention, what I claim is:

1. A blasting medium consisting of ammonium nitrate coated with sulphur and charcoal, and mingled with whole black blastng powder.

2. A blasting medium consisting of an oxygen carrying explosive salt of the class 

